1 files changed, 69 insertions, 0 deletions
diff --git a/al/eax_fx_slot_index.h b/al/eax_fx_slot_index.h
new file mode 100644
index 00000000..95ff9313
--- /dev/null
+++ b/al/eax_fx_slot_index.h
@@ -0,0 +1,69 @@
+#ifndef EAX_FX_SLOT_INDEX_INCLUDED
+#define EAX_FX_SLOT_INDEX_INCLUDED
+
+
+#include <cstddef>
+
+#include "eax_api.h"
+
+
+using EaxFxSlotIndexValue = std::size_t;
+
+
+class EaxFxSlotIndex
+{
+public:
+    EaxFxSlotIndex() noexcept = default;
+
+    EaxFxSlotIndex(
+        EaxFxSlotIndexValue index);
+
+    EaxFxSlotIndex(
+        const EaxFxSlotIndex& rhs) noexcept;
+
+    void operator=(
+        EaxFxSlotIndexValue index);
+
+    void operator=(
+        const GUID& guid);
+
+    void operator=(
+        const EaxFxSlotIndex& rhs) noexcept;
+
+
+    bool has_value() const noexcept;
+
+    EaxFxSlotIndexValue get() const;
+
+    void reset() noexcept;
+
+    void set(
+        EaxFxSlotIndexValue index);
+
+    void set(
+        const GUID& guid);
+
+    operator EaxFxSlotIndexValue() const;
+
+
+private:
+    [[noreturn]]
+    static void fail(
+        const char* message);
+
+
+    bool has_value_{};
+    EaxFxSlotIndexValue value_{};
+}; // EaxFxSlotIndex
+
+
+bool operator==(
+    const EaxFxSlotIndex& lhs,
+    const EaxFxSlotIndex& rhs) noexcept;
+
+bool operator!=(
+    const EaxFxSlotIndex& lhs,
+    const EaxFxSlotIndex& rhs) noexcept;
+
+
+#endif // !EAX_FX_SLOT_INDEX_INCLUDED